1. Field of the Invention
The invention relates to a method and an arrangement for contactless energy transmission during charging of a vehicle battery, e.g., of an electric car.
2. Background Information
It is already known to charge the battery of electric vehicles by means of inductive charging stations (Rhein-Main-Presse, Jul. 18, 1992). To this end, a charging coil is manually inserted into the slot of an adapter disposed on the outside of the vehicle, and electrical energy is subsequently transmitted from the charging device to the battery. Although this system of energy transmission operates reliably and is safe to use, since the secondary coil is protected in the adapter, the insertion of the charging coil into the adapter is oriented toward conventional fueling of a gasoline-powered car and is rather awkward in terms of handling. Moreover, the consequences of having the adapter disposed on the outside of the electric car can include mechanical, aerodynamic and aesthetic disadvantages to the vehicle. Another disadvantage is a path-impairing cable is connected to the electric car, and is in place for a significantly longer time during charging of the battery than, for example, the connection of a gasoline hose to a gasoline vehicle. Furthermore, charging devices that have different charge outputs and are produced by different manufacturers should be able to be coupled to the vehicle without great effort. Slow charging with a home charging device that has a low output and fast charging using a high-output charging device, for example in a parking garage while the owner shops, will become standard practice. Because the dimensions of the charging coil vary with the output, in an arrangement that includes a coil to be pushed into a slot, both the slot and the coil must be of the dimensions of the highest output.
Therefore, the problem exists of achieving simple and convenient handling in addition to high operating and application reliability during charging of the battery of an electric car. It is to be noted here that, on the one hand, simple and convenient handling of such a system, without an excessively high mechanical outlay, requires easy accessibility to the inductive energy-transmission components, but, on the other hand, the greater danger of impairment of the operating reliability and safety in use exists because of the stronger association with environmental influences, particularly pollution or the like.